Long line loiter technique

ABSTRACT

A unique technique for remotely locating a mass tethered by means of a tow-line to a fixed wing aircraft in a loiter position over, or on a selected target by initially forming the tethered tow line into a long loop preferably by use of a high drag device, while the mass is held within the aircraft, and subsequently free falling the mass from the aircraft to its remote, loiter position on target, while the aircraft is engaged in an on-pylon circling maneuver to thereby stall the line.

ite States atent [191 Simous [54] LONG LINE LOITER TECHNIQUE [75]Inventor: John C. Simons, Dayton, Ohio [73] Assignee: The United Statesof America as represented by the Secretary of the Air Force [22] Filed:Dec. 10, 1970 [21] Appl. No.: 97,413

[ 1 Apr. 3, 1973 3,141,641 7/1964 Beadle et al. ..244/138 R 3,167,2781/1965 Roberge ..89/1.5 X

OTHER PUBLICATIONS National Geographic, Vol. 133, No. 2, February, 1968,page 294.

Primary Examiner-Samuel W. Engle Attorney-Harry A. Herbert, Jr. andArthur R. Parker [5 7] ABSTRACT A unique technique for remotely locatinga mass tethered by means of a tow-line to a fixed wing aircraft in aloiter position over, or on a selected target by initially forming thetethered tow line into a long loop preferably by use of a high dragdevice, while the mass is held within the aircraft, and subsequentlyfree falling the mass from the aircraft to its remote, loiter positionon target, while the aircraft is engaged in an on-pylon circlingmaneuver to thereby stall the line.

5 Claims, 10 Drawing Figures PATENIEDAPR3 ms 3,724,817

' sum 1 or 3 INVENTOR. 4/0 C. SI

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PATENIEDAPR 3 I973 3,724,817 SHEET 2 or 3 INVENTOR. ddlV/V C. /M

LONG LWE LOITER TECHNIQUE BACKGROUND OF THE INVENTION This inventionrelates generally to the remote positioning of a towed mass over aselected target area from a fixed wing aircraft engaged in a circlingmaneuver.

In the development, for example, of the positioning of ordance on targetby U. S. strike aircraft, various delivery techniques have beenpreviously proposed, many of which have actually been used in combat.These techniques all have had one common purpose; namely, to enable theaircraft to effectively engage the target, while minimizing its requiredtime over the target area and thus reducing its opportunity for loss ordamage from hostile small arms fire. A similar proposal that has beenpreviously studied and which is considered of great applicability inthis area has involved a suggested technique for retrieving objects, inwhich the aircraft circles a preselected pick-up site while paying out atethered pick-up line, the end of which is to loiter at the pick-upsite. In this proposal, the aircraft is supposed to continue to circleuntil the line moves into an equilibrium state whereby the lower endthereof is to describe a circle around the pickup site at the sameangular velocity as the circling aircraft, but of a much smallerdiameter. However, this suggested method, as well as other similarproposals previously studied, have involved the use of a single and longtow-line, which has been found to be particularly sensitive to one ormore of four main problems, which have previously curtailed furtherdevelopment; namely, the problem of vertical bounce (yo-yo) of the mass,elliptical motion of the mass, difficulty in maintaining a constantradius turn, and the effects of wind and turbulence. The presentinvention, to be hereinafter summarized and described in detail, wasdeveloped to eliminate or, at least drastically reduce, the effects ofthe aforementioned problems involved in the previously-suggested use ofa relatively long and single tow line.

SUMMARY OF THE INVENTION The present invention consists briefly in thepositioning and holding of a mass tethered to an aircraft at the end ofa long tow line at the center of an on-pylon circling maneuver,preferably by use of a high drag device consisting of a high-drag coneslidably mounted on the line, or a parachute fixed thereto to initiallyuniquely form the line into a long loop, prior to the release of thetethered mass from the aircraft. Afterwards, the mass is released whilethe aircraft proceeds into the on-pylon circling maneuver to therebystall the line and thus permit the line and mass to fall to a loiterposition over, or on the target area.

Other objects and advantages of the invention will become readilyapparent from the following disclosure thereof, taken in connection withthe accompanying drawings, in which;

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational andpartly schematic view of the maneuver aircraft and improved long lineloiter technique of the present invention, illustrating the initialformation of the tow line into a relatively long loop, and the positionof the tethered mass from the towing aircraft just after its initialrelease therefrom;

FIG. 2 is a front and partly schematic view, illustrating both theaircraft of FIG. I after its entry into an onpylon circling maneuver,and the stabilization of the tethered line and mass attached thereto in,or preparatory to, its repositioning in loiter over, or on the targetarea;

FIGS. 3 and 3a respectively illustrate side elevational and front views,partly schematic, of a unique modified form of the improved long lineloiter technique of the present invention, as it may be applied to adoublemass system, in which a second mass may be fixed to the tetheredline at a preselected distance above the first mass attached at the endthereof;

FIG. 4 is still another front view, partly schematic, of second,modified form of the double-line delivery technique of the presentinvention, as it is applicable to a para-loiter system, in which aparachute may be attached as shown to the tow-line at a relatively shortdistance above the mass supported thereby;

FIG. 5 is a further partly schematic, side elevational view,illustrating the basic launch configuration of the invention;

FIG. 6 is a schematic and fragmentary view, showing use of selected massslide devices that may be applica- -ble to the improved long line loitertechnique of the DESCRIPTION OF THE PREFERRED EMBODIMENT Referringgenerally to the drawings and, in particular, to FIG. 1 thereof, a towline to which the novel long line loiter deployment technique of thepresent invention may be applied is illustrated generally at 12 as beingtethered to a fixed wing-type aircraft indicated schematically at 10. Amain mass, depicted by the relatively large, perforated cone-likeelement at 11, is shown attached to one end of the tow line 12, theother end of which naturally being wrapped around any standard-type ofreel mechanism (not shown) that may be mounted within the aircraft. Whenit is desired to remotely position the mass 11 in loiter position over,or on a selected target, or at a pick-up site, the aircraft 10 is, ofcourse, initially flown to the target area. At this time, the novel longline loiter technique taught by the present invention may be employed byinitially deploying the tow line 12, which may in one application be2,000 feet in length, into a long loop, indicated generally at 12a,while holding the cone-mass 11 in the aircraft. This long loop, ineffect, creates a double-line. During initial tests of this double-linesystem, it was found that knots developed in both sections of the towline l2 and,' therefore, a small sliding cone, indicated at 13, wasthereafter used both to eliminate such knots and to act as a relativelyhigh drag device operating to hold constant tension on, and thusensuring the maintenance of the long loop or double-line 12a initiallyformed in the tow line 12. After forming the tow line 12 into theaforesaid long loop 12a, in one test thereof, the cone-mass 11 wasthereafter level-bombed from the aircraft 10 from an altitude ofapproximately 900 to 1,000 feet. The position of this mass 1 1 shortlyafter exiting from the aircraft 10 is depicted in the view of theaforementioned FIG. 1. Immediately after dropping the mass 11 from theaircraft 10, the latter is flown into a constant bank orbitapproximating an on-pylon circling maneuver, as is illustrated in FIG.2, for the specific purpose of stalling and, in this manner, allowingthe tow line 12 with the mass 11 attached thereto to freefall in asubstantially vertical direction and at the approximate center of theon-pylon maneuver to the selected target or pick-up site. In thisregard, during tests of the above-described long line loiter technique,which may be designated the Double-Line, Free-Fall delivery method,considerable and improved stability of of the towed mass in loiterposition was evident when the towing aircraft being used was able tocomplete a total of 27 orbits in a 15 knot wind while a ground observerhand held the attached mass. During this time, the tow line, as at 12,never touched the ground.

A second delivery method, utilizing the present long line loiter ordouble-line free-fall technique, involves the application thereof whenthe mission of the delivery aircraft 10 requires its flight at lowskip-bomb altitudes. In this event, the tow line 12 would initially beonly partially deployed into the inventive long loop or doublelineconfiguration to avoid excessive lays of the line on the ground. Thus,after delivery of the mass 11 on, or at the target site in the samemanner described hereinbefore, the aircraft 10 would be maneuvered outof its circling attitude into a straight-and-level configuration, andthe line 12 would be fully deployed as full power is applied to theaircraft in a tight climbing spiral.

The present improved long line loiter or double-line free fall methodhas been found applicable to a second modified delivery technique inwhich, as is seen particularly in FIGS. 3 and 3a, a second, highcone-shaped mass, as at 14, is depicted attached to the tow line 12 at aposition thereon above, and in spaced relation, to the low mass 15attached to the end of the tow line. The cone mass 14 may be affixed tothe line 12 from l-200 feet above the mass 15. Again, as in the case ofthe invention form of FIGS. 1 and 2, the tow line 12 is initially payedor reeled-out of the aircraft while both high and low masses 14, 15 areretained within the aircraft, and while the latter is instraight-and-level flight. After the line 12 has been fully deployedinto the long loop or double-line configuration 12a of the presentinvention, the double-mass arrangement 14 and 15 is then level-bombedfrom the aircraft 10 as the latter is once again maneuvered into theon-pylon circling maneuver with the selected target, as at 16 (Note FIG.3a) oriented at the center thereof.

With the aforementioned double-line, double mass technique, improvedaccuracy of delivery was achieved in actual tests by initially allowingthe lower mass 15 to free fall to an impact position on the ground at apoint A" (FIG. 3a) near, but to one side (the upwind side) of the target16. Thereafter, the aircraft 10 continued in its orbit until theairborne cone-mass 14 arrived at a loiter position over the target 16.Its positioning on the said target 16 was then achieved either byreeling out more of the tow line 12, or by lowering the aircraft 10.

The previously-described double-line, free-fall and double-mass,double-line delivery methods also offer the inherent capability ofpromoting the continuous delivery of selected masses on, or immediatelyover a designated target area, as for example where it is desired tosaturate such an area with ordnance. In this event, light high-explosiveordnance in the form of solid cluster bomb units, as is indicatedgenerally at 19, for example, in the schematic, fragmentary view of FIG.6, may be continuously slid down the loitering tow-line 12 for groundimpact in the area of the target at 21, after breaking-01f the said lineon striking the mass-device at 20. The latter action is also used to armthe said ordnance. The device 20 could also represent a wide-anglecamera for recording the actual explosions for later bomb damageassessment.

With particular reference to FIG. 4 of the drawings, the presentinvention is shown applied to, and forming an integral part of stillanother delivery method, known as the Para-Loiter delivery method, inwhich the apex of a parachute, as at 17, may be attached by a groundobserver at a pick-up site to the tow line 12 at a relatively shortdistance of from -200 feet, for example, above a mass 18 that is afiixedto the end thereof. Of course, in one application, the mass 18 could bepreviously remotely positioned in loiter over the pick-up site by theformation of the double loop configuration in, and the circlingmaneuver-deployment of, the tow-line 12 involved in thepreviouslydescribed, novel double-line, free-fall delivery means of thepresent invention. As an alternative arrangement, the parachute 17 witha mass, such as 18, already suspended thereto could be attached to thetow-line at the pick-up site, or the parachute 17 and mass 18 could bothbe attached within the aircraft, if desired.

In the event the parachute 17 has been affixed to the tow-line 12 (NoteFIG. 4) at the aforementioned pickup site, the aircraft 10 would thenleave orbit and enter into a straight-and-level flight condition, atwhich time the ground observer would release the parachute l7 andattached mass 18 from the pick-up site, and thus provide for thelaunching thereof into trail behind the aircraft. In this regard, FIG. 5depicts the basic initial launch configuration involving application ofthe present invention with the mass 18 shown attached to the tow line12. Naturally, in the para-loiter delivery method, the previously-notedparachute 17, in deflated condition, would be attached to the tow-line12, as was previously-described in connection with FIG. 4. Subsequently,the aircraft would arrive over a predesignated target area where itwould be maneuvered into a turn towards the towed parachute 17 and mass18, the maneuver being similar to the previouslynoted on-pylon maneuver.The latter action results in placing slack in the tow-line 12 and, ineffect, again forms substantially the same-type of double-loopconfiguration instrumental in accomplishing the long line loitertechnique of the present invention, as has been previously described.This slackening of the tow-line 12 naturally stalls it, and therebypermits the mass 18 to begin to fall and initially effect a partialinflation and opening of the parachute 17 into a crescent-shaped highdrag airfoil. The mass 18 continues to fall and the parachute 17thereafter fully opens. The aircraft 10 continues its circling maneuveraround the open parachute 17 until ground contact or a pre-selectedminimum altitude in loiter is reached by the parachute, whichconfiguration would be substantially that depicted in FIG. 4,particularly for a no-wind situation. The aircraft 10, afteraccomplishing its mission, would then fly away from the parachute 17,and the parachute I7 and attached mass 18 would once more beautomatically launched into trail behind the aircraft. Therefore, withthis para-loiter arrangement, the parachute 17 uniquely acts both as apassive sensor, and as a high drag device, lifting surface during trailand, finally, as a slow descent loiter device.

Although the elements 11, 15 and 18 of the inventive forms of FIGS. 1, 3and 5 have each been described simply as a mass, it is to be understoodthat they may represent any one or more of a number of different devicesto be employed, for example, either by US. strike aircraft in combat, orby other aircraft engaged in peacetime pursuits. Thus, for instance, onesuch device would be the already-referred to camera 20 of FIG. 6, or itcould consist of a loudspeaker positioned either at the high mass 14 ofFIG. 3 or at the mass 18 of FIG. 4, or, alternatively, many otherselected devices could be utilized, such as aerial display signs, orremotely positioned anti-fire explosives or dilutors.

With particular reference to FIGS. 7, 8 and 9, the aircraft at 10 isdepicted as employing a still further modified form of the presentinvention, in which the remote sampling of soil and water located on theearths surface may be accomplished from the air by the modified use ofthe unique long line loiter system of the present invention. To thisend, once again the towline, indicated generally at 12, may be initiallydeployed from the aircraft 10, as the latter approaches the selectedground site, into the inventive long loop or double-line configurationat 12a, while a mass at 22 attached to the end of the said line and a3-foot parachute at,23 attached to the line 12 at a position thereonapproximately 400 feet above the mass 22 are retained the aircraft. Fortest purposes, a targetmass at 24 was positioned on the ground, and theaircraft 10 was then flown in a straight pass at approximately 500 feetover the target 24 (FIG. 7), as the previously-noted airborne mass 22was then parachuted by means of the parachute 23 to the ground positionrepresented by the said target 24 for a total of 8 seconds of contact.This delivery method is different from the previously-described methodsin that the aircraft 10 is never turned during delivery or pick-up. Inthis regard, it is noted that in practice the mass 22 would actually bea particular device designed to accomplish the requisite picking up ofeither a soil or a water sample.

In the view of FIG. 7, the tow-line 12, after the initial parachuting ofthe mass 22 from the aircraft 10, gives an overall appearance ofincorporating three separate lines, although only one line is actuallyutilized, and, therefore, the present system of FIGS. 7, 8 and 9 hasbeen designated the S-Line Pickup. In this connection, after release ofthe mass 22 and parachute 23, the mass 22 actually assumes a positionapproximately 100 feet above the ground shortly after its ejection fromthe aircraft, since the short-line portion at 12b is approximately 400feet in length, and the aircraft 10 is being flown at an altitude ofabout 500 feet, as previouslynoted. However, since on exiting from theaircraft 10, the parachute 23 is initially in deflated condition, themass 22 largely assumes the momentum imparted to it by the aircraft and,accordingly, it actually initially swings into a position somewhatbeyond the designated ground target at 24. Immediately thereafter, ofcourse, the parachute 23 opens and its substantial drag effect nullifiesthe said momentum and causes the mass 22 and its 400 foot short line 12bto swing backwards to a vertical position towards the target 24. Ofcourse, since the parachuted mass 22 has, now also been descendingtowards the ground, its initial release from the aircraft 10 at theproper position results in its impact on the ground target 24, and theconfiguration substantially depicted in FIG. 8 is assumed.

As depicted in the view of the aforementioned FIG. 8, the high line or,in other words, the initially formed double-line configuration at 12acontinues to uncoil its loop as the aircraft 10 retreats or flies awayfrom the target 24. The tow-line 12 shortly thereafter assumes a singleline configuration and thus lifts or launches the parachute 23 and mass22 into trail behind the aircraft 10. Prior to its assumption of thefull trail position, the now deflated or folded parachute 23 acts toenhance the verticality of the launch by serving as a lifting surfaceunder tow, as is schematically depicted in the view of FIG. 9.

Thus, a new and improved basic technique for remotely positioning anaircraft-towed mass representing a selected device to be employed ordelivered over, or on a predesignated target or pick-up site has beendeveloped by the unique and yet simplified long line loiter technique ofthe present invention. Moreover, by use of the present double-linetechnique, a selected mass may be air delivered in loiter positioneither ballistically on target, or particularly by use of the doublemasstechnique, utilized to deliver other slidably mounted masses to theselected target site, or by application of the para-loiter technique,greatly facilitate the remote positioning of selected masses on targetat near zero velocities and, in addition, promote the retrieval of suchmasses for delivery at a second site.

I claim:

1. In means for delivering an airborne device, adapted to be towed froma fixed wing aircraft, in a relatively stable and extended loiterposition on, upwind of, or over a selected ground site, and up toconsiderable distances away from the flight path of the aircraft, thesteps including; initially providing for the attachment of the deviceat, or near the free end of a single, unitary tow cable adjustablyaffixed at its other end to the aircraft and providing the sole andotherwise unrestrained connection between thedevice and the aircraft;said tow cable having a combined cable-deploying andcable-tension-applying mass slidably positioned thereon; next, flyingthe aircraft initially in a substantially straight-line mode over,upwind of, or near the selected ground site, depending on the existenceof a wind, and its direction and velocity and/or the type of devicebeing employed; then deploying all, or at least a substantial portion ofthe tow cable in a relatively long and narrow loop-double-lineconfiguration initially in extended trail behind the aircraft, by theconcerted action resulting from the ejection and paying out from theaircraft of a significant and intermediate portion of the cable throughthe simultaneous release therewith of the combined cable-deploying andcable-tension-applying mass slidably positioned on the cable, and theretention of the device and the free end of the cable attached theretowith the aircraft until the length of the doubleline configurationdesired for the cable and compatible with the release altitude of theaircraft has been achieved; subsequently releasing the free end of thecable and the device attached thereto by level-bombing from theaircraft; and immediately thereafter stalling the cable and attacheddevice by maneuvering the aircraft into a substantially constant bank,on-pylon -type of circling line maneuver, with the pylon/center thereofbeing thereby definitely placed over, or upwind of the selected groundsite, and the stalled device being oriented in direct alignment with thesaid pylon/center and thereby being automatically restrained by the saidon-pylon maneuver, to a positive free fall and paying out of thedouble-line portion of the tow cable, until the said device has arrivedat a relatively stabilized and prolonged loiter position over, or on theselected ground site.

2. ln means for delivering an airborne device in loiter position on, orover a selected ground site as in claim 1, wherein the initial step ofattaching the device to the tow cable further comprises the additionalsteps of providing both for the attachment of the said device at aposition on the tow cable above the end thereof and thereforeconstituting a first, relatively high mass to be deployed with the towcable in the said loiter position above the selected ground site; and asecond, low mass affixed to the end of the tow cable and constituting ananchor means impacting adjacent, and to one side of the selected groundsite, during the aircraft maneuvering step, to thereby positively ensurethat the loiter position of the device is oriented at a substantiallyfixed location over said ground site.

3. ln means for delivering an airborne device in loiter position on, orover a selected ground site as in claim 2, wherein the free-fall of thedevice to said loiter position initially resulting from the aircraftmaneuvering step further includes the additional step of still furtherdeploying the tow cable from the aircraft to thereby lower the anchoredfirst, high mass, constituting the device to be deployed, on theselected ground site.

4. In means for delivering an airborne device in loiter position on, orover a selected ground site or target as in claim 1, wherein the stepcomprising maneuvering the aircraft into an on-pylon/circling linemaneuver to thereby stall the tow cable still further includes theadditional step of attaching the apex of a parachute to the tow cable ata relatively short distance above the device to thereby provide for themore stable parachute delivery thereof to a loiter position at near zerovelocity after the aerial transport towing of the selected device from apick-up site to the selected ground site.

5. In means for delivering an airborne, water or soil sampling device,adapted to be towed from a fixed wing aircraft by an elongated, singleunitary tow cable having a first, free end and a second, restrained endadjustably affixed to the aircraft, on a selected group or water targetsite, the steps comprising; initially providing for the attachment tothe said free end of the tow cable of the said device, and for thefurther attachment of a parachute at a substantial and predetermineddistance above the said free end and thereby respectively dividing theoverall tow cable into a relatively short, lower cable portion directlyattached to the device and a relatively long, upper cable portionaffixed to the aircraft; then retaining the device, the free end andrelatively short, lower cable portion, and the parachute within theaircraft; thereafter, upon flying the aircraft over the selected targetsite in a straight pass, deploying the said relatively long, upper cableportion in a double-line configuration that is relatively long bycomparison to the length of the said relatively short, lower cableportion, while retaining the aircraft in straight-and-level flight, bythe simultaneous release therewith of a cable tension-applying massslidably positioned on said cable; and, immediately after completing thedeployment of the said relatively long, upper cable portion into thedouble-line configuration, releasing said airborne, water and/orsoil-sampling device, and the parachute attached to the said relativelyshort, lower cable portion, while simultaneously and continuouslymaintaining the aircraft in a straight pass over and beyond the targetsite, to thereby parachute the device to the selected site from the drageffect produced by the automatic inflating of the said parachutethereafter nullifying the momentum initially imparted to the device,upon its release from the aircraft, and causing it to swing in an arcrearwardly past the selected ground or water target site, to thus bringthe device back to a vertically-disposed and descending conditiondirectly over and effecting contact with the selected ground or watertarget site.

1. In means for delivering an airborne device, adapted to be towed froma fixed wing aircraft, in a relatively stable and extended loiterposition on, upwind of, or over a selected ground site, and up toconsiderable distances away from the flight path of the aircraft, thesteps including; initially providing for the attachment of the deviceat, or near the free end of a single, unitary tow cable adjustablyaffixed at its other end to the aircraft and providing the sole andotherwise unrestrained connection between the device and the aircraft;said tow cable having a combined cable-deploying andcable-tension-applying mass slidably positioned thereon; next, flyingthe aircraft initially in a substantially straight-line mode over,upwind of, or near the selected ground site, depending on the existenceof a wind, and its direction and velocity and/or the type of devicebeing employed; then deploying all, or at least a substantial portion ofthe tow cable in a relatively long and narrow loop-double-lineconfiguration initially in extended trail behind the aircraft, by theconcerted action resulting from the ejection and paying out from theaircraft of a significant and intermediate portion of the cable throughthe simultaneous release therewith of the combined cable-deploying andcable-tension-applying mass slidably positioned on the cable, and theretention of the device and the free end of the cable attached theretowith the aircraft until the length of the double-line configurationdesired for the cable and compatible with the release altitude of theaircraft has been achieved; subsequently releasing the free end of thecable and the device attached thereto by level-bombing from theaircraft; and immediately thereafter stalling the cable and attacheddevice by maneuvering the aircraft into a substantially constant bank,on-pylon -type of circling line maneuver, with the pylon/center thereofbeing thereby definitely placed over, or upwind of the selected groundsite, and the stalled device being oriented in direct alignment with thesaid pylon/center and thereby being automatically restrained by the saidon-pylon maneuver, to a positive free fall and paying out of thedouble-line portion of the tow cable, until the said device has arrivedat a relatively stabilized and prolonged loiter position over, or on theselected ground site.
 2. In means for delivering an airborne device inloiter position on, or over a selected ground site as in claim 1,wherein the initial step of attaching the device to the tow cablefurther comprises the additional steps of providing both for theattachment of the said device at a position on the tow cable above theend thereof and therefore constituting a first, relatively high mass tobe deployed with the tow cable in the said loiter position above theselected ground site; and a second, low mass affixed to the end of thetow cable and constituting an anchor means impacting adjacent, and toone side of the selected ground site, during the aircraft maneuveringstep, to thereby positively ensure that the loiter position of thedevice is oriented at a substantially fixed location over said groundsite.
 3. In means for delivering an airborne device in loiter positionon, or over a selected ground site as in claim 2, wherein the free-fallof the device to said loiter position initially resulting from theaircraft maneuvering step further includes the additional step of stillfurther deploying the tow cable from the aircraft to thereby loWer theanchored first, high mass, constituting the device to be deployed, onthe selected ground site.
 4. In means for delivering an airborne devicein loiter position on, or over a selected ground site or target as inclaim 1, wherein the step comprising maneuvering the aircraft into anon-pylon/circling line maneuver to thereby stall the tow cable stillfurther includes the additional step of attaching the apex of aparachute to the tow cable at a relatively short distance above thedevice to thereby provide for the more stable parachute delivery thereofto a loiter position at near zero velocity after the aerial transporttowing of the selected device from a pick-up site to the selected groundsite.
 5. In means for delivering an airborne, water or soil samplingdevice, adapted to be towed from a fixed wing aircraft by an elongated,single unitary tow cable having a first, free end and a second,restrained end adjustably affixed to the aircraft, on a selected groupor water target site, the steps comprising; initially providing for theattachment to the said free end of the tow cable of the said device, andfor the further attachment of a parachute at a substantial andpredetermined distance above the said free end and thereby respectivelydividing the overall tow cable into a relatively short, lower cableportion directly attached to the device and a relatively long, uppercable portion affixed to the aircraft; then retaining the device, thefree end and relatively short, lower cable portion, and the parachutewithin the aircraft; thereafter, upon flying the aircraft over theselected target site in a straight pass, deploying the said relativelylong, upper cable portion in a double-line configuration that isrelatively long by comparison to the length of the said relativelyshort, lower cable portion, while retaining the aircraft instraight-and-level flight, by the simultaneous release therewith of acable tension-applying mass slidably positioned on said cable; and,immediately after completing the deployment of the said relatively long,upper cable portion into the double-line configuration, releasing saidairborne, water and/or soil-sampling device, and the parachute attachedto the said relatively short, lower cable portion, while simultaneouslyand continuously maintaining the aircraft in a straight pass over andbeyond the target site, to thereby parachute the device to the selectedsite from the drag effect produced by the automatic inflating of thesaid parachute thereafter nullifying the momentum initially imparted tothe device, upon its release from the aircraft, and causing it to swingin an arc rearwardly past the selected ground or water target site, tothus bring the device back to a vertically-disposed and descendingcondition directly over and effecting contact with the selected groundor water target site.